At present, a wearable device is rapidly developing due to advantages such as portability; however, a size and a weight of the wearable device limit a battery capacity of the wearable device, which leads to a problem of short standby time and affects user experience. For example, a pair of GOOGLE GLASS equipped with a 570 milliampere hour (mAh) battery can be used for only three to four hours. In addition, wireless charging is drawing greater attention due to convenience of charging.
An existing wireless charging technology is only a simple substitution of a wired charging manner. When an existing wireless charging device is working, a charging process and a user service are independent of each other. However, in a process of actual use, electric power consumption of a device is closely related to a use degree of an application service. For example, a smartphone can be used for more than two days if used only for conversation, but can be used for only one day if used as a wireless terminal to run various applications such as audio/video downloading and playing, web page browsing, and photographing.
The existing wireless charging technology cannot meet differentiated electric power requirements.